Stress cracking of plastics by gasoline and gasoline components

Abstract

AbstractThe susceptibility of polycarbonate, polymethyl methacrylate, and cellulose acetate butyrate to gasoline‐induced stress cracking was evaluated by measuring the critical strains of specimens exposed to a variety of commercial gasolines and gasoline components. Cellulose acetate butyrate exhibited the greatest resistance to gasoline followed by polymethyl methacrylate and polycarbonate. Stress cracking was a complex function of gasoline composition. Measured critical strains generally decreased and the severity of cracking of molded parts generally increased as the total aromatic content of the gasolines increased. However, a significant difference in critical strains was observed between the individual aliphatic components of gasoline. No correlation was observed between critical strain and gasoline type, i.e., premium, regular, or unleaded. The effect of time of exposure was examined, and it was observed that for some binary mixtures splashing caused much more severe cracking than continuous exposure.